| dc.description.abstract | Transcranial magnetic stimulation (TMS) is a non-invasive method of stimulation that acts on the brain and is used for both medical and scientific purposes. By accurately simulating what happens inside neurons affected by TMS the results of patient treatment may improve.
To understand what happens during TMS, it is important to have a look at the physics involved. The basic principle is that a time-varying current through a loop of coiled metal wire produces a magnetic field, which induces electric fields. These electric fields then affect neurons. The physics is described in further detail using what appears to be the established consensus. Although there seems to be an established consensus for the basic physics involved, all the processes that takes part in TMS are yet to be fully understood.
Following the path set by others and describing each step in great detail, a model has been created that calculates the current induced inside the neuron, where the neuron is represented as a series of compartments. This induced current is then inserted into compartmental simulation models and the development of the membrane potential of the neuron is simulated for a period of time. The peak current through the coil for these simulations was adjusted to fit the peak magnetic flux density measured for some TMS coils of about 2 Tesla.
The model is made with isolated neurons in mind, but more complex situations could be handled by allowing NEURON to simulate with extracellular potentials and calculating those potentials, although this is outside the scope of this thesis.
The long term goal is to eventually include computational tools for magnetic stimulation of neurons in the toolkit of LFPy. | |
